Remove tui_first_data_element_no_in_line

tui_first_data_element_no_in_line is never used.  This patch removes
it.  Tested by rebuilding, and by grep.

gdb/ChangeLog
2019-06-22  Tom Tromey  <tom@tromey.com>

	* tui/tui-windata.h (tui_first_data_element_no_in_line): Don't
	declare.
	* tui/tui-windata.c (tui_first_data_element_no_in_line): Remove.
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 78ea6cf..29c568f 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,11 @@
 2019-06-22  Tom Tromey  <tom@tromey.com>
 
+	* tui/tui-windata.h (tui_first_data_element_no_in_line): Don't
+	declare.
+	* tui/tui-windata.c (tui_first_data_element_no_in_line): Remove.
+
+2019-06-22  Tom Tromey  <tom@tromey.com>
+
 	* tui/tui-data.h (tui_del_window, tui_del_data_windows): Don't
 	declare.
 	* tui/tui-data.c (tui_del_window, tui_del_data_windows): Remove.
diff --git a/gdb/tui/tui-windata.c b/gdb/tui/tui-windata.c
index 8616b6c..646adfb 100644
--- a/gdb/tui/tui-windata.c
+++ b/gdb/tui/tui-windata.c
@@ -64,23 +64,6 @@
 }
 
 
-/* Answer the index of the first element in line_no.  If line_no is
-   past the data area (-1) is returned.  */
-int
-tui_first_data_element_no_in_line (int line_no)
-{
-  int first_element_no = (-1);
-
-  /* First see if there is a register on line_no, and if so, set the
-     first element number.  */
-  if ((first_element_no = tui_first_reg_element_no_inline (line_no)) == -1)
-    { /* Looking at the general data, the 1st element on line_no.  */
-    }
-
-  return first_element_no;
-}
-
-
 /* Function to delete all the item windows in the data window.  This
    is usually done when the data window is scrolled.  */
 void
diff --git a/gdb/tui/tui-windata.h b/gdb/tui/tui-windata.h
index 63fca0d..56bf1ed 100644
--- a/gdb/tui/tui-windata.h
+++ b/gdb/tui/tui-windata.h
@@ -29,7 +29,6 @@
 extern void tui_check_data_values (struct frame_info *);
 extern void tui_display_data_from_line (int);
 extern int tui_first_data_item_displayed (void);
-extern int tui_first_data_element_no_in_line (int);
 extern void tui_delete_data_content_windows (void);
 extern void tui_refresh_data_win (void);
 extern void tui_display_data_from (int, int);